diff options
| -rw-r--r-- | fs/btrfs/backref.c | 46 |
1 files changed, 31 insertions, 15 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index a1a00a7bdba5..dc276ce3afe0 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1674,32 +1674,36 @@ int btrfs_find_all_leafs(struct btrfs_backref_walk_ctx *ctx) * the current while iterating. The process stops when we reach the end of the * list. * - * Found roots are added to @ctx->roots, which is allocated by this function and - * @ctx->roots should be NULL when calling this function. This function also - * requires @ctx->refs to be NULL, as it uses it for allocating a ulist to do - * temporary work, and frees it before returning. + * Found roots are added to @ctx->roots, which is allocated by this function if + * it points to NULL, in which case the caller is responsible for freeing it + * after it's not needed anymore. + * This function requires @ctx->refs to be NULL, as it uses it for allocating a + * ulist to do temporary work, and frees it before returning. * - * Returns 0 on success, < 0 on error. On error @ctx->roots is always NULL. + * Returns 0 on success, < 0 on error. */ static int btrfs_find_all_roots_safe(struct btrfs_backref_walk_ctx *ctx) { const u64 orig_bytenr = ctx->bytenr; const bool orig_ignore_extent_item_pos = ctx->ignore_extent_item_pos; + bool roots_ulist_allocated = false; struct ulist_iterator uiter; int ret = 0; ASSERT(ctx->refs == NULL); - ASSERT(ctx->roots == NULL); ctx->refs = ulist_alloc(GFP_NOFS); if (!ctx->refs) return -ENOMEM; - ctx->roots = ulist_alloc(GFP_NOFS); if (!ctx->roots) { - ulist_free(ctx->refs); - ctx->refs = NULL; - return -ENOMEM; + ctx->roots = ulist_alloc(GFP_NOFS); + if (!ctx->roots) { + ulist_free(ctx->refs); + ctx->refs = NULL; + return -ENOMEM; + } + roots_ulist_allocated = true; } ctx->ignore_extent_item_pos = true; @@ -1710,8 +1714,10 @@ static int btrfs_find_all_roots_safe(struct btrfs_backref_walk_ctx *ctx) ret = find_parent_nodes(ctx, NULL); if (ret < 0 && ret != -ENOENT) { - ulist_free(ctx->roots); - ctx->roots = NULL; + if (roots_ulist_allocated) { + ulist_free(ctx->roots); + ctx->roots = NULL; + } break; } ret = 0; @@ -2295,6 +2301,11 @@ int iterate_extent_inodes(struct btrfs_backref_walk_ctx *ctx, ctx->bytenr); ASSERT(ctx->trans == NULL); + ASSERT(ctx->roots == NULL); + + ctx->roots = ulist_alloc(GFP_NOFS); + if (!ctx->roots) + return -ENOMEM; if (!search_commit_root) { struct btrfs_trans_handle *trans; @@ -2302,8 +2313,11 @@ int iterate_extent_inodes(struct btrfs_backref_walk_ctx *ctx, trans = btrfs_attach_transaction(ctx->fs_info->tree_root); if (IS_ERR(trans)) { if (PTR_ERR(trans) != -ENOENT && - PTR_ERR(trans) != -EROFS) + PTR_ERR(trans) != -EROFS) { + ulist_free(ctx->roots); + ctx->roots = NULL; return PTR_ERR(trans); + } trans = NULL; } ctx->trans = trans; @@ -2344,8 +2358,7 @@ int iterate_extent_inodes(struct btrfs_backref_walk_ctx *ctx, root_node->val, ctx->bytenr, iterate, user_ctx); } - ulist_free(ctx->roots); - ctx->roots = NULL; + ulist_reinit(ctx->roots); } free_leaf_list(refs); @@ -2358,6 +2371,9 @@ out: up_read(&ctx->fs_info->commit_root_sem); } + ulist_free(ctx->roots); + ctx->roots = NULL; + return ret; } |